Phacops and other trilobites from Emsian age beds of the Delorme Formation, Mackenzie Mountains, Northwest Territories

Abstract

The trilobite genus Phacops is documented for the first time in northwestern or Arctic Canada from Emsian age beds of the Delorme Formation, western Mackenzie Mountains. Phacops natlenis n. sp. is described; it shows closest morphologic affinity to P. spedeni Chatterton from late Emsian age beds of southeastern Australia. Other Emsian trilobite genera from the Delorme Formation in the Sekwi Mountain map-area, Mackenzie Mountains include: Lacunoporaspis, Ceratarges?, Acanthopyge (Mephiarges), Leonaspis, and Koneprusia?.